This invention relates to platforms for removable containers, and more particularly to apparatus for securing large removable containers to such platforms.
Large containers of many sizes and types are often used to transport various kinds of loads. For example, these containers may be used to carry compacted refuse away from a stationary refuse compactor, or they may be used to haul debris away from the site of a major construction project. Generally, the containers can be filled when sitting on the ground, floor, or other surface, loaded onto a vehicle such as a truck or a railroad car, transported to a remote point, unloaded from the vehicle, and then emptied. These containers may be of extremely large size. For example, a large refuse container may measure over 20 feet in length and may hold up to 45 cubic yards of material.
Vehicles of the type shown in U.S. Pat. No. 3,107,020, granted to George R. Dempster et al on Oct. 15, 1963, that transport these containers have a container support platform or tilting frame pivotally secured to the rear portion of the vehicle chassis. The tilting frame can pivot between a travel position and a tipped position, and these vehicles have a pair of hydraulic cylinders pivotally secured to both the chassis and the tilting frame for pivoting the frame between the travel and tipped positions. In the travel position, the tilting frame is generally horizontal and is resting on the chassis of the vehicle. In the tipped position, the tilting frame slopes downward toward the ground with the back end of the tilting frame in contact with the ground. Commonly, the tilting frame will have a cable and cable drawing means such as an electric powered winch drum or a hydraulic cylinder. One end of the cable is free, and the cable drawing means can be employed to draw the free end of the cable towards the front end of the tilting frame.
To pick up a container, the tilting frame is pivoted to the tipped position and the free end of the cable is attached to the end of the container closest to the vehicle. The cable is then drawn in and the container is pulled up onto the sloping frame. The tilting frame includes guide rails positioned longitudinally across the frame. These guide rails cooperate with longitudinal members of the container undercarriage to insure that, as the container is pulled onto the tilting frame, the longitudinal axes of the frame and the container are in general alignment. After the container is on the tilting frame, the frame is returned to its travel position so that the container will be in a horizontal position as it is transported by the vehicle to another location. To unload the container, the tilting frame is again pivoted to the tipped position and the free end of the cable is lowered toward the ground so that the container slides down the frame to the ground.
It is desirable to carry a container in a position which distributes the weight of the container approximately equally between the axles supporting the tilting frame. This prolongs the life of the axles reducing the cost of maintaining the vehicle. Also, distributing the container's weight equally among the axles permits that weight to be distributed evenly among the road wheels supporting the tilting frame. This extends the useful life of the wheels further reducing the cost of maintaining the vehicle. The weight of the container is usually sufficient to hold the container in place on the tilting frame. However, securing devices are often used to insure against any undesired movement of the container.
The problem of securing a container to the tilting frame is complicated by the fact that various sizes and types of containers involving numerous structural designs are in common use. The multiplicity of structural designs makes it difficult to develop a single securing device that can be used interchangeably with the different containers. In the past, a variety of clamping devices and procedures have been used to secure containers to the tilting frame. Such procedures, though, are subject to operator error and are time consuming. Also, these procedures often utilize clamping mechanisms having numerous removable parts. These parts are frequently lost, mislaid, or damaged while removed from the clamping mechanism. The bother of continuously clamping and unclamping containers and the risk of loss or damage to the removable parts make these clamping procedures unsatisfactory.